package a01demo1;

import java.util.ArrayList;
import java.util.Collections;

public class Test2 {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        Collections.addAll(list, "a", "b", "c", "d");
        Collections.shuffle(list);
        String s = list.get(0);
        System.out.println(s);
    }
}
